Display panels are used in a wide variety of applications such as home and commercial televisions, laptop and desktop computers and indoor and outdoor advertising and information presentations. Flat panel displays are only a few inches thick in contrast to the deep cathode ray tube monitors found on most televisions and desktop computers. Flat panel displays are a necessity for laptop computers, but also provide advantages in weight and size for many of the other applications. Currently laptop computer flat panel displays use liquid crystals which can be switched from a transparent state to an opaque one by the application of small electrical signals. It is difficult to reliably produce these displays in sizes larger than that suitable for laptop computers. Plasma displays have been proposed as an alternative to liquid crystal displays. A plasma display uses tiny pixel cells of electrically charged gases to produce an image and requires relatively large electrical voltages and power to operate.
Flat panel displays having a cathode using a field emission electron source, i.e., a field emission material or field emitter, and a phosphor capable of light emission upon bombardment by electrons, have been proposed. Such displays have the potential for providing the visual display advantages of the conventional cathode ray tube and the depth, weight and power consumption advantages of the other flat panel displays. U.S. Pat. Nos. 4,857,799 and 5,015,912 disclose matrix-addressed flat panel displays using micro-tip cathodes constructed of tungsten, molybdenum or silicon. WO 94/15352, WO 94/15350 and WO 94/28571 disclose flat panel displays wherein the cathodes have relatively flat emission surfaces.
It has been discovered, see for example WO 95/22169, that a cathode comprised of fibrous electron field emitters, wherein the fibers lie essentially in the plane of the cathode and emission is achieved at desired regions along the length of the fiber, have advantages over previously disclosed cathodes. The fibrous cathode is supported by a substrate and further improved performance is achieved when the portions of the fibrous cathode addressed, and from which electron emission occurs, are suspended and not in direct physical contact with the substrate.
The instant invention provides a method for connecting, both electrically and mechanically, a field emission fiber to a substrate. Other objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description and drawings which follow hereinafter.